Tiny MP3 players are great, but the tiny means of navigation they often employ can be a big pain in the ass. The Minput project explores the possibility of using optical sensors to let those devices double as mice.

The project comes from Carnegie Mellon University's Human-Computer Interaction Institute, and even in these early stages the sensors can register both horizontal and vertical movements as well as flicks, slides and twists. All of this input goodness is demonstrated impressively in a photo album concept in the video above, allowing the user to keep his or her (comparatively) fat fingers off the device's small screen.

The prototype has the optical sensors on a long board mounted to the bottom of the device, but the Carnegie Mellon researchers say they could easily be implemented to existing form factors without adding too much bulk. Best of all: they're just run of the mill sensors, and the parts only come out to a few bucks a pop altogether. That being said, next year when the guy on the plane next to you is furiously rubbing his iPod on their crotch, try to think back to this post. [PopSci]